Formats

Parameters

ending
file in the range to delete; must end with a zero (default=bfile +
9)

numdays

number
of days of real-time data to store online; the range is 2 to 9 (default=4)

Remarks

The QRTMDG command is used to maintain the "cylinders" of
real-time MD and grid files. The cylinders are groups of ten files whose file
number is based on the last digit of the Julian date. For example, data from
day 135 are stored in files 5, 15, 25, etc., and data from day 310 are stored
in files 10, 20, 30, etc. Since each cylinder consists of ten files you can
keep up to nine days of data online. QRTMDG is used to delete all but the numdays most
recent files in each cylinder. For example, if you run QRTMDG with a value
of 4 in numdays on day 135, the real-time files for days 135, 134,
133 and 132 are retained.

SSEC recommends scheduling QRTMDG to run at 00:01 UTC daily to delete the
old MD and grid files from your real-time cylinders.

QRTMDG works during the transition to a new year by determining the Julian
date of the next day and deleting the files for that day. For example, running
QRTMDG on day 002 will delete files 3, 13, 23,... (which contained day 363
data) so they can be written when data for day 003 arrives.

Due to the cylinder structure and day numbering during the transition to a
new year (from days ...,364, 365 to 001, 002,...) there are limits to the number
of days of data you can keep online between days 365 and 008 because, for example,
MD file 4 can store data for day 364 or 004, but not both. During a non-leap
year transition (e.g., 2005-2006), the constraints limit you to a maximum of
four files on day 004; five files on days 003 and 005; six files on days 002
and 006; seven files on days 001 and 007; and eight files on days 365 and 008.
During a leap year transition (e.g., 2008-2009), the constraints limit you
to five files on days 003, 004 and 005; six files on days 002 and 006; seven
files on days 001 and 007; and eight files on days 366 and 008.

If you store four or less days of data (five or less days during leap year
transitions), QRTMDG works as expected because there are no day numbering conflicts.
For example, running QRTMDG each day with a numdays value of 4 retains
surface hourly MD files 5, 4, 3, 2 on day 365; files 1, 5, 4, 3 on day 001;
files 2, 1, 5, 4 on day 003, etc.

Example

SKE
2006129 00:01:00 999999 24 "QRTMDG MD 1 40 4

This example
stores the current day's MD data plus the previous three days for MD files
in the range 1 to 40. When this command runs on day 2006307, all MD files in
the range 1 to 40 are deleted except: 4, 5, 6, 7, 14, 15, 16, 17, 24, 25, 26,
27, 34, 35, 36 and 37.